Best place to purchase Holley idle feed restrictors?

[hunt2elk]

Where are you guys buying these small Quick Fuel/Holley jets? I have 4 corner idle so I need a set of 4. Summit list them for 6.54 + 8.99 shipping, and Jegs sells them individually for 1.69 + 6.99 shipping. These are the only places I can find that even sells them. Kind of gets me on the shipping as these are so small that 4 of them would easily go in a standard envelope with a 50 cent stamp.

 

[beanhead]

You try amazon?

 

[hunt2elk]

Yep, nothing on Amazon. Ended up finding one guy on ebay that sells them. $14.96 for a set of 4 shipped, which is still crazy money for what they are imo.

 

[68 HEMI GTS]

There expensive little buggers, buy a bag of blanks and drill them yourself. You can usually find them on eBay. Just need a good numbered drill set.

I use 6-32 set screws ( drill to suit) and move them to the lower position like most of the original holley’s. You just need a 6-32 bottoming tap. Pretty easy conversion. “Suppose” to help the idle quality. IMO it has on the carbs I’ve converted so I just automatically do it now. You can also buy the set screws in bulk.

 

[hunt2elk]

There expensive little buggers, buy a bag of blanks and drill them yourself. You can usually find them on eBay. Just need a good numbered drill set.

I use 6-32 set screws ( drill to suit) and move them to the lower position like most of the original holley’s. You just need a 6-32 bottoming tap. Pretty easy conversion. “Suppose” to help the idle quality. IMO it has on the carbs I’ve converted so I just automatically do it now. You can also buy the set screws in bulk.

View attachment 619907 View attachment 619908 View attachment 619909

Curious as to what kind of change in idle air/fuel readings you are experiencing with a 1 number change in ifr size?

 

[68 HEMI GTS]

Kinda depends on how close you are, I normally move atleast 2 sizes. You going down? What’s your current setup?

 

[hunt2elk]

The car runs and idles great with no soot in the tailpipes, but the idle A/F mixture was 12. I messed around going up 6 sizes on the idle air bleeds first. That helped somewhat as far as A/F, but the car ran like crap everywhere else. So I dropped back down 5 sizes to I believe to 71's. Came stock with 31 ifr's. From the reading I have done, everyone stated that a one size change there will make a 7% difference. Holley told me to go with 30's, so I did. I am now up to 12.6-12.7 at idle. Would have been more, but after that change I had to open my idle mixture screws from 7/8 to 1 turn out.

 

[68 HEMI GTS]

Ideally they idle best around 13.5 range in neutral if timing and everything is correct. Not sure what kind of carb it is but you may need to add transfer slot restrictors to clean up the off idle cruise. I’d say you're close on the IAB. Try a .028-.029IFR. Shouldn’t need to go any smaller than that. TSR would be my next move after the IAB.

What happens if you lean the idle screws a bit right now with the current IFR’s?

 

[hunt2elk]

What happens if you lean the idle screws a bit right now with the current IFR’s?

The carb is a Quick Fuel QS750. If I turn in the idle mixture screws 1/8, my vac goes from 11 to 9.5 and the idle rpm goes down.
Is it normal when downsizing the ifr's to have to open up the idle mixture screws? Seems counter productive?

 

[68 HEMI GTS]

The carb is a Quick Fuel QS750. If I turn in the idle mixture screws 1/8, my vac goes from 11 to 9.5 and the idle rpm goes down.
Is it normal when downsizing the ifr's to have to open up the idle mixture screws? Seems counter productive?

Yes, it’s a balancing game. Smaller you go the more you have to open the screws up. Remember those ifr’s Are feeding fuel to the transfer slots as well as your idle screws. That’s were it sometimes helps to start limiting what the transfer slot can pull if you get to a point where your idle screws are good. I’d bet if you lower the ifr that would help you out (position wise). Could be some of the reason it wants more fuel to behave. How much transfer slot is showing pri & sec?

 

[hunt2elk]

How much transfer slot is showing pri & sec?

They are both square right now.